Longest Common Prefix
Updated Jan 31, 2026
Problem
Write a function to find the longest common prefix string amongst an array of strings.
If there is no common prefix, return an empty string "".
Constraints
- 1 <= strs.length <= 200
- 0 <= strs[i].length <= 200
- strs[i] consists of only lowercase English letters
Examples
Example 1
Input:
strs = ["flower", "flow", "flight"]
Output:
"fl"
Example 2
Input:
strs = ["dog", "racecar", "car"]
Output:
""
There is no common prefix among the input strings.
Function Signature
def longestCommonPrefix(self, strs: list[str]) -> str
How to Submit
Implement a Solution class with a longestCommonPrefix method.
Your method will be called with the input parameters and should return the answer.